We are in the process of submitting a RFP for a new requirement to one of our customer. We have two options in the design and we would like to discuss the pros and cons of this design. We have two L3 Switches (3550) and both the L3 switches are connected to edge Router as indicated in diagram. The Edge Routers have WAN links to customer and the requirement is when the serial in R1 goes down, the entire traffic should get diverted through R2 serial. One is idea is to bring both L3 Switches and both edge Routers in same HSRP group and track the R1 serial from L3-SW1. When R1 serial goes down, the traffic will get diverted through L3-SW2, then R2 serial.
The other option is configure the HSRP between only both the edge Routers (R1 & R2) and in that case we need a L2 Switch to connect both L3 and both the edge Routers. In that case, we will track the serial of R1 from RI Ethernet only and in case serial goes down, the traffic will get diverted to R2 serial. In that case both L3 switches will be in one HSRP group and both edge Routers will be in different HSRP group and we need a Layer2 Switch. FYI , We dont want do Load balancing between both the WAN links . At any point of time , traffic will go through only one WAN link as our applications will not support load balancing.
Your thoughts are appreciated.